494 



NATURE 



[August i6, 19 17 



THE BRITISH SYNTHETIC COLOUR 

 INDUSTRY IN WAR TIME. 



THE lecture delivered to the Society of Arts by 

 Mr. C M. Whitaker in December last merits 

 a more than passing notice as illustrating the 

 difficulties in the way of British dye producers during 

 the war period and the manner in which a commend- 

 able degree of success has been obtained in coping 

 with the dye shortage. It deserves to be more gener- 

 ally known that even before the war British firms 

 were already opposing a resolute front to German 

 competition. These firms not only issued pattern- 

 cards and circulars comparable in style with those sent 

 out by their foreign rivals, but they also dealt with 

 the difficulty of language by printing these manuals 

 of instruction in the principal European tongues. Even 

 in 1906 these instructions had been furnished by the 

 pioneer firm of Read Holliday and Sons, Ltd., in all 

 these languages, i.nd also in Japanese. Very early in 

 the development of the colour industry this firm had 

 acquired the Schutzenberger and Lalande patent for 

 dyeing indigo by the modern scientific process with 

 hydrosulphite, and even to-day the older dyers some- 

 times refer to this method of indigo dyeing as the 

 " Holliday " vat. 



The lecturer pointed out from his own personal 

 knowledge that the practice of sending out practical 

 dyers to assist the firm's clientele of dye-users in their 

 application of the colouring matters is not exclusively a 

 German procedure. The above-mentioned firm and 

 its 'successors, British Dyes, Ltd., have afforded their 

 customers this expert assistance for more than thirty 

 years. 



At the outbreak of war the British dye industry 

 was in the hands of four or five firms, who together 

 controlled a capital not greatly exceeding half a million 

 sterling, and the problem confronting this group of 

 industrialists was how to replace the former German 

 import of dyes having an annual value of about 

 i,8oo,oooL Even in peace times such a problem would 

 be incapable of immediate solution, but taking into 

 account the disti actions of war, the results obtained 

 in the last two years are distinctly encouraging. The 

 vulnerable point in the British position was not, how- 

 ever, that of lack of capital, but rather the bad habit 

 which had arisen of buying from abroad intermediate 

 products which could with comparatively little expert 

 knowledge be converted into finished dyes. An addi- 

 tional handicap arising from this cause was ihe short- 

 age of chemists having the necessary works experience. 

 Attention is being concentrated on these two vital 

 points. The two leading firms, British Dyes, Ltd., 

 and Messrs. Levinstein, Ltd., have taken into their 

 employment a large number of college-trained chemists, 

 some of whom are exercising their talent for research 

 on the essential intermediates, while others are acquir- 

 ing works experience in the supervision of industrial 

 processes and in the handling of men. 



It is impossible for those untrained in organic 

 chemistry to have any correct perception of the amoufit 

 of preliminary work which precedes the production 

 of a coal-tar dye. The complete manufacture of an 

 ordinary synthetic black may involve twenty-one dis- 

 tinct chemical operations. Other modern products re- 

 quire even more processes. The British dye firms cer- 

 tainly deserve full credit for their success in coping 

 with the vitally urg'-nt requirements of the Allied 

 Governments in equipment colours. One British firm 

 alone furnished the military authorities with 145,0001b. 

 of wool khaki dves in the fateful month of December, 

 1915, when Army requirements were increasing to an 

 enormous extent. This supply of wool khaki dyes has 

 been maintained, together with prodigious amounts of 

 cotton and linen khaki colours. The armies of our 



NO. 2494, VOL. 99] 



Italian and Russian Allies have also been largely sup- 

 plied from British sources. The appearance of the 

 uniforms of soldiers returning on leave is the best 

 testimonial to the fastness of British-made khaki dyes, 

 showing that these colours can withstand the severest 

 war conditions. 



In the valuable discussion which followed the 

 lecture the points of interest raised were the 

 question of the multiplicity of names for the same 

 dye and the possibility of simplification in this respect, 

 the Germa.i monopoly of bromine, and the relations 

 of the dye-producing industry and teaching institu- 

 tions. G. T. Morgan. 



THE ROTATION OF THE MOON.^ 



AN interesting resume of the progress of our know- 

 ledge of the moon's rotation, together with a 

 considerable amount of original work, is given in the 

 memoir before us. The author recalls the remarkable 

 control which the earth exerts on the rotation ; the 

 line joining the poles of the moon's equator and orbit 

 always passes through the pole of the ecliptic, which 

 lies between them, i\° from the first, 5^" from the 

 second ; both poles revolve round the pole of the ecliptic 

 in i8-6 years. The earth's action has also forced the 

 period of rotation to coincide with that of revolution ; 

 the existence of this action is still in evidence 

 from the fact that all secular and long- 

 period terms in the moon's revolution have 

 their counterpart in the rotation; for example, 

 the secular acceleration in longitude has not 

 the effect of making us gradually see a dilTerent 

 hemisphere. 



Much attention has been given of late years to the 

 "physical libration," especially the annual term, which 

 is considerably the largest. Different determinations 

 of its coefficient show a surprisingly large range ; the 

 largest value is that of M. Puiseux, 19- 1', derived from 

 forty Paris photographs covering a period of fifteen years ;"■ 

 the other values range from 57' to 10'. We have to 

 -divide these figures by 220 to obtain the apparent shift 

 seen from the earth. This gives 52" for the Pujseux 

 value ; it does not appear that the numerous meridian 

 observations of the crater Mosting A will permit of so 

 large a value. 



In studying the problem mathematically, the author 

 makes use of some methods introduced by MM. Zinner 

 and Charlier, which have appeared in earlier Medde- 

 landen. He denotes the three principal moments of 

 inertia of the moon by A, B, C. A is about the 

 diameter pointing towards the earth, and C about the 

 axis of rotation. The three ratios (C-A)/A, (C-B)/B, 

 (B — A)/^, are denoted .by fe,, fej, fej- It is shown that 

 stability demands that B be greater than A, i.e. the 

 moon's equator is elongated towards the earth; if 

 fei, fej have different signs, C lies between A and B, 

 and the rotation is unstable. It is shown that fe,, k, 

 may be either both positive or both hegative; in the 

 first case C, B, A are in descending order of mag- 

 nitude, in the second case B, A, C; the latter \yould 

 involve rotation about the long-est axis, which is in 

 teresting as a theoretical possibility, but it is shown 

 later not to be the actual case. Hence k,, k. are both 

 positive, fei is stated to be about 0000627 ; the values 

 of fej corresponding with the physical libration co- 

 efficients of Franz, Hayn, and Puiseux are 0000314. 

 0000157, and 0001178 respectively. The last value 

 makes fej negative, and therefore indicates unstable 

 motion, another reason for coYicluding that the Puiseux | 

 coefficient is too high. However, it is shown^ that 

 controlled rotation may exist, even when the conditions 

 of stability are not satisfied. 



1 " Uber die Rotation des Mondes." Von Axel Jonsson. Meddelanden of 

 Lund Observatory, ser. ii., No. 15. (Lund : C. W. K. Gleerup, 1917-) 



